Essential thrombocythemia (ET): When to start hydroxyurea (HU)?

Thank you for the reactions and I'm glad to see a new post, too. The posts are helpful and reassuring to me, as all this is new for me.

I want to be part of an active discussion as my treatment progresses. Thank y'all and God bless!

Hi all, I was diagnosed with ET about 15 years ago. They first tried anagrelide but it gave me awful headaches. Then they put me on hydroxyurea every other day. After a while I started taking it every day and now it's 2 on Monday, Wednesday and Friday 1 a day the rest of the days. My numbers are still over 600 typically. You will find that if you have injuries or surgeries the numbers will spike. I go for labs every 4 months to keep a check on it. I never had any reaction at all to the hydroxyurea. I guess im lucky that way.
I was shocked to hear it was a cancer because the doctors in the past just called it a blood disorder.
I have was diagnosed with stage 3 melanoma in January 2022. I went through 13 months of immunotherapy and I've been cancer free since then. As little as about 10 years ago melanoma would have been a death sentence and now it's treatable! So hopefully there may be more effective treatments for ET than aspirin and hydroxyurea. So hang in there...

Hi Ana,

Your question and comments and the replies are already helpful to me; my thanks to all.

I just found this forum and this page popped up. I don't know if anyone will see this reply but here goes.

My story and limited knowledge, so far:

I've recently been diagnosed with JAK-2 positive ET and sent to a specialist. Other causes of my high platelet count were ruled out but no blood marrow biopsy was done. My platelets have been slowly and steadily increasing for quite some time and are now 518k. Everything else is normal. The specialist said if they get above 600k he will put me on Hydrea. He said it is a chemo drug, but not to freak out because for most people it is well tolerated and "just a pill you have to take." He said for most people it doesn't make you throw up or lose your hair. He also said ET can (rarely) progress to a form of leukemia in a very small percentage of cases, or cause blood marrow problems, but the biggest danger is blood clots which can cause strokes, heart attacks, or go to the lungs fatally. He put me on a low-dose aspirin a day to make the platelets less sticky. Btw, I have no real symptoms, just the high platelet counts.

I've of course been reading like crazy about this disorder and the drug. I just finished reading two clinical studies tonight and then found this forum from the same Google search. I'll share what they said. Some of it was Greek to me but some was in plain English.

The studies reassured me (and I hope they will reassure you), because both agreed Hydrea (by any of its names) is often the first line treatment for ET, especially for people over the age of 60 or who have had previous blood clots. Much younger people may be given something else first. I haven't had clots but I'm 78, so I sure qualify age-wise! (Yes, I know I'm blessed to not have had the problem sooner.) The studies showed that Hydrea did reduce blood clot (they used the medical name) events, and had a lower incidence of causing leukemia than some of the other drugs that could be used for ET. The studies reassured me. (I hate to take meds because I know they go all over your body and can do unintended things, but I know sometimes they can be life savers.)

My specialist said they don't know what causes ET, nor how to prevent it, and nothing I did caused it. It's not known to be hereditary (thankfully) and is rare. It's not curable but is treatable, and the prognosis is good. He said it is technically a form of blood cancer but he'd prefer to call it a blood disorder or blood condition. It's not invasive. It was a bit unsettling to have to go to a cancer center but I'm thankful to have good doctors nearby. From what I've read life expectancy is about normal, especially for those 60 or older. At my age I probably shouldn't worry about ET!

The PA I also met told me I'll likely have to go on Hydrea because I'm already so close to 600k. I think, just as with all meds, we have to weigh the risks to the benefits. Hydrea has a very small risk of causing leukemia, but ET itself also has (maybe a larger?) chance of causing it, too. And the risk of fatal blood clots is a huge factor.

All the replies here have made me feel so much better about having to take this drug, if I do. I admit I didn't want to even think about it. I have to go back in 3 months. THANK YOU, THANK YOU, all!

And Ana, good luck to you, and everyone else, with your treatment. I share your concerns. Please post how you are currently doing.

(Sorry so wordy. I'm a fast typist which is probably a forum curse, LOL.)

J. (cec2)

Oh, boy, I really relate to the fight/flight/freeze of caregiving and relief after death. I was diagnosed about the time my mother started going downhill. I started HU the month before she died. Fortunately, the HU improved fatigue so I could deal with clearing out her house and deal with her estate. My husband was a saint the entire year we had to deal with that mess.

I share honestly with trusted friends about my ET, symptoms, fears and bad times. I think sharing openly with the right people is helpful for me and those I share with to deepen the trust between this. Positivity can at times be toxic! Empathy can be healing whether giving or receiving. Wonky mitral here, too and mild aortic stenosis. I believe my CALR mutation and the blood pressure increase leading to cardiac issues to be caused by the high stress of caretaking of family member with insufficient help. I lived in state of fight/flight/freeze for over a year. My initial response to the death was relief from witnessing the suffering AND letting go of my responsibilty for responding to constant emergencies. Though my diagnoses didnt come until much later, I link the long term stress to the cause. Diagnoses knocked me to my knees for a while! On hydroxyurea for almost a year now and finally getting platelets down below 600. Its a shotgun treatment, not a rifle.

anavleek, as if it weren't confusing enough . . . some doctors say ET is a blood cancer. Others say it is a blood disorder.

ET is triggered (90% of the time) when, for unknown reasons, one of the three proteins that govern platelet production experiences a mutation. (Ten percent of the time, there is no protein mutation. This is referred to as triple negative ET.)

With that mutation, the protein "drives" the blood marrow to produce excessive and misshapen (abnormal) platelets.

Producing abnormal cells is a definition of cancer.

Like many MPN topics, this issue is strongly debated. I personally feel ET is cancer, others may see it in a different way.

If we agree to call ET cancer, note that it is not an acute cancer, such as the cancers that produce tumors. Instead, it is a chronic cancer. It can't be cured but it can be managed.

Speaking personally, accepting that I have a chronic cancer motivates me to take my chemo capsules and work out every day. Maybe this will not extend my life. But it will make every day I have better.

Does any of that make sense?

Basically your doctor disagrees with the majority of hematologists and MPN specialists about ET's reclassification as a cancer around 2006. As long as the doc is following accepted treatment protocols, your care plan may still be the same as everyone else's--test for driver mutations, monitor blood every few months, take baby aspirin, start HU when you are in the high risk zone, and visit at least once a year.

If it were me, I would ask why your doc doesn't agree with the cancer designation. The answer might tell me something about his attitudes, whether he keeps up with new info, and what kind if care I can expect.

I am confused about ET being a cancer my hemp/onco told me it is not a cancer but a blood disorder ?!?

By working closely with your O/H, taking baby aspirin and staying active, you're taking great care of yourself, lalalura.

anavleek, for me at least HU not only brought down my platelet count, it also gave me my energy back, and relieved those killer ET headaches.

Not only do we have a weird cancer, we all go through it a bit differently.

I guess that makes us very special.